Endoscope

Abstract

An endoscope includes an operating body having a knob, a flexible insertion tube having a bending tube part, to be inserted into an object to be observed, and wires for bending the bending tube part by operating the knob. The bending tube part includes ring link members having a tubular form, and flexible connection members for coupling adjacent two ring link members at upper and lower or left and right sides thereof, alternately, to connect the ring link members with one another in series.

What is claimed is: 
     
       1. An endoscope comprising: an operating body having an operating knob thereon;   a flexible insertion tube connected to the operating body, including a flexible tube part, a bending tube part and an end part, in series; and   wires for bending the bending tube part of the flexible insertion tube by operating the operating knob,   the bending tube part comprising:   ring link members having peripheral holes, the wires passing through the peripheral holes; and   flexible connection members for coupling two adjacent ring link members at alternate pairs of sides to connect the ring link members with one another in series, each connection member being composed of a single flexible elongate member which is flexible in a direction approximately perpendicular to its longitudinal direction, the opposite ends of each flexible connection member being secured to the ring link members.   
     
     
       2. The endoscope of claim 1, wherein each link ring member includes four peripheral holes at four sides, and each flexible connection member has a tubular form and includes a through-hole, and wherein each flexible connection member is secured at the peripheral holes of the two adjacent ring link members, and the wires pass through the holes of the flexible tubular connection members. 
     
     
       3. The endoscope of claim 2, wherein each peripheral hole is a double diameter hole composed of a larger hole and a smaller hole connected thereto, and wherein each flexible tubular connection member having the through-hole is secured in the larger hole, and the wires pass through both the small holes and the through-holes of the flexible tubular connection members. 
     
     
       4. The endoscope of claim 1, wherein each ring link member also includes four peripheral retainers at four sides, separate from the peripheral holes of each ring link member, and the flexible connection members are secured to the ring link members at the four peripheral retainers. 
     
     
       5. The endoscope of claim 4, wherein each peripheral retainer includes a hole therein in which the flexible connection member is secured. 
     
     
       6. The endoscope of claim 4, wherein each peripheral retainer includes a groove therein in which the flexible connection member is secured. 
     
     
       7. The endoscope of claim 1, wherein each ring link member includes peripheral wire guide members each having a hole through which the wire passes. 
     
     
       8. The endoscope of claim 1, wherein the flexibility of the flexible connection members is gradually reduced from the front end portion to the rear end portion of the bending tube part. 
     
     
       9. The endoscope of claim 1, wherein the flexible connection members are flexible in the transverse direction to their longitudinal axes when a bending stress is applied thereto, but are not deformed in the longitudinal direction thereof when a compression stress is applied to the flexible connection members. 
     
     
       10. The endoscope of claim 2, wherein the flexible connection member comprises a metal coil. 
     
     
       11. A bending tube part comprising: ring link members having peripheral holes, the wires passing through the peripheral holes; and   flexible connection members for coupling two adjacent ring link members at alternate pairs of sides to connect the ring link members with one another in series, each flexible connection member being composed of a single flexible elongate member which is flexible in a direction approximately perpendicular to a longitudinal direction thereof, opposite ends of each flexible connection member being secured to the ring link members.   
     
     
       12. The endoscope of claim 11, wherein each link ring member includes four peripheral holes at four sides, each flexible connection member having a tubular form includes a through-hole, and wherein each flexible connection member is secured at the peripheral holes of the two adjacent ring link members, and the wires pass through the holes of the flexible tubular connection members. 
     
     
       13. The endoscope of claim 12, wherein each peripheral hole is a double diameter hole composed of a larger hole and a smaller hole centered therein, and wherein each flexible tubular connection member having the through-hole is secured in the larger hole, and the wires pass through the small holes and also through the through-holes of the flexible tubular connection members. 
     
     
       14. The bending tube part of claim 11, wherein each ring link member also includes four peripheral retainers at four sides, separate from the peripheral holes of each ring link member, and the flexible connection members are secured to the ring link members at the four peripheral retainers. 
     
     
       15. The endoscope of claim 14, wherein each peripheral retainer includes a hole therein in which the flexible connection member is secured. 
     
     
       16. The endoscope of claim 14, wherein each peripheral retainer includes a groove therein in which the flexible connection member is secured. 
     
     
       17. The endoscope of claim 11, wherein each ring link member includes peripheral wire guide members, each having a hole through which the wire passes. 
     
     
       18. The endoscope of claim 11, wherein the flexibility of the flexible connection member is gradually reduced from the front end portion to the rear end portion of the bending tube part. 
     
     
       19. The endoscope of claim 11, wherein the flexible connection members are flexible in the transverse direction thereof when a bending stress is applied to the flexible connection members, but are not deformed in the longitudinal direction thereof when a compression stress is given to the flexible connection members.